A photovoltaic module having a desired appearance

Abstract

The present disclosure provides a photovoltaic module having a desired appearance. The module comprises at least one solar cell having black or dark surface portions. The module further comprises a material layer positioned over the black or dark surface portions. The material layer has material portions being lighter in colour or appearance than the black or dark surface portions. The material portions have a transmissivity for visible light dependent on a composition and/or thickness of the material portions. The material layer is at least largely transmissive for light at areas between the material portions. A visible layer is positioned over the material layer and includes at least one of: an image, a pattern or a colour. The thickness, composition and/or lateral coverage of the material portions of the material layer are selected dependent on a desired contrast and/or a darkness, brightness or colour of features of the desired appearance of the photovoltaic module.

1 . A photovoltaic module having a desired appearance, the module comprising:
 at least one solar cell having black or dark surface portions;   a material layer positioned over the black or dark surface portions of the at least one solar cell, the material layer having material portions being lighter in colour or appearance than the black or dark surface portions of the at least one solar cell, the material portions having a transmissivity for visible light dependent on a composition and/or thickness of the material portions, the material layer being at least largely transmissive for light at areas between the material portions; and   a visible layer positioned over the material layer and including at least one of: an image, a pattern or a colour; wherein the thickness, composition and/or lateral coverage of the material portions of the material layer are selected dependent on a desired contrast and/or a darkness, brightness or colour of features of the desired appearance of the photovoltaic module.   
     
     
         2 . The photovoltaic module of  claim 1  wherein the material layer comprises a plurality of islands provided in the form of dots. 
     
     
         3 . The photovoltaic module of  claim 2  wherein the dots have a local thickness dependent on desired contrast and/or a darkness or brightness of features of the desired appearance of the photovoltaic module. 
     
     
         4 . The photovoltaic module of  claim 2  wherein at least some of the dots are sufficiently thin such that the dots have a transmissivity for visible light dependent on the thickness of the dots. 
     
     
         5 . The photovoltaic module of  claim 2  wherein at least the majority of the dots have a thickness within the range of 0-5 μm and are largely invisible to the naked eye. 
     
     
         6 . The photovoltaic module of  claim 2  wherein the dots have a composition dependent on desired contrast and/or a darkness or brightness of features of the desired appearance of the photovoltaic module. 
     
     
         7 . The photovoltaic module of  claim 6  wherein the dots have a transmissivity dependent on the composition of the dots. 
     
     
         8 . The photovoltaic module of  claim 6  wherein the dots comprise non-transparent ink and a transparent ink or varnish. 
     
     
         9 . The photovoltaic module of  claim 8  wherein the dots have, dependent on a desired local transmissivity, a composition including 0-20%, 20-40%, 40-60%, 60-80% or 80-100% transparent ink or varnish with the remainder being a non transparent ink whereby a transmissivity of the dots depends on the composition of the dots. 
     
     
         10 . The photovoltaic module of  claim 2  wherein the dots are formed using a digital printing process. 
     
     
         11 . The photovoltaic module of  claim 2  wherein the visible layer includes a printed image formed within the visible layer without the use of back colour, even though features of the image as visualised from outside of the photovoltaic module appear black or dark. 
     
     
         12 . The photovoltaic module of  claim 11  wherein the image is printed using the colours cyan, magenta and yellow only. 
     
     
         13 . The photovoltaic module of  claim 2  wherein a diameter of the dots of the material layer and distance between the dots determines a coverage of the material layer selected dependent on a desired contrast and/or a darkness or brightness of features of the desired appearance of the photovoltaic module. 
     
     
         14 . The photovoltaic module of  claim 2  wherein the dots have a diameter of 50 μm-200 μm and gaps between adjacent dots have an extension of 20-40 μm, 40-60 μm, 60-80 μm and 80-100 μm such as 30 μm. 
     
     
         15 . The photovoltaic module of  claim 2  wherein the thickness and/or composition of the dots of the material layer and properties of the image of the visible layer are selected such that at least the majority or all areas of visible layer and the material layer have a transmissivity for visible light greater than zero. 
     
     
         16 . The photovoltaic module of  claim 2  wherein the thickness of the dots is reduced to 70% or less,
 50% or less, 30% or less, 20% or less even to 10% less of the minimal thickness at which the dots would block transmission of visible light through the dots by more than 90%. 
 
     
     
         17 . The photovoltaic module of  claim 2 , wherein a composition of the dots is changed by increasing a percentage amount of transparent ink for forming the dots to 30% or more, 50% or more, 70% or more, 80% or more or even 90% or more. 
     
     
         18 . The photovoltaic module of  claim 2  wherein the at least one solar cell is a cadmium telluride (CdTe)-based solar cell. 
     
     
         19 . The photovoltaic module of  claim 1 , wherein the visible layer is a first visible layer positioned over a first major surface of the at least one solar cell, wherein the photovoltaic module further comprises a second visible layer including at least one of: a colour, an image and a pattern, and wherein the second visible layer is positioned over a second major surface of the at least one solar cell and which is opposite the first major surface such that the first and second visible layers are visible at opposite sides of the at least one solar cell. 
     
     
         20 . The photovoltaic module of  claim 2  wherein a layer of clear varnish or transparent ink is positioned over the material layer to substantially equalise height differences of the dots and substantially fill gaps between adjacent dots. 
     
     
         21 . A method of forming a photovoltaic module having a desired appearance, the method comprising the steps of:
 providing at least one solar cell having black or dark surface portions;   forming a material layer over the black or dark surface portions of the at least one solar cell, the material layer having material portions being lighter in colour or appearance than the black or dark surface portions of the at least one solar cell, the material portions having a transmissivity for visible light depending on a thickness and/or composition of the material portions, the material layer being at least largely transmissive for light at areas between the material portions; and   forming a visible layer, the visible layer including at least one of: an image, a pattern or a colour;   wherein the material layer is positioned between the black or dark surface portions of the at least one solar cell and the visible layer, and wherein forming the material layer comprises selecting the thickness, composition and/or lateral coverage of the material portions of the material layer dependent on a desired contrast and/or a darkness, brightness or colour of features of the desired appearance of the photovoltaic module.   
     
     
         22 . The method of  claim 21  wherein the step of forming the material layer and/or forming the visible layer comprises digital printing, such as digital UV printing or digital ceramic printing. 
     
     
         23 . The method of  claim 21  wherein the material portions of the material layer are dots. 
     
     
         24 . The method of  claim 23  wherein the dots have a thickness in the range of 0-10 μm or 0-5 μm. 
     
     
         25 . The method of  claim 23  wherein the dots have a diameter of 50 μm-200 μm and gaps between adjacent dots have an extension of 20-40 μm, 40-60 μm, 60-80 μm and 80-100 μm such as 30 μm. 
     
     
         26 . The method of  claim 23  wherein forming the material layer comprises selecting a desired thickness variation of the dots within the material layer. 
     
     
         27 . The method of  claim 23  wherein forming the material layer comprises a sequence of printing procedures, wherein a selection of dots is printed over dots printed in a previous procedure resulting in an increase in thickness, further comprising selecting for each printing sequence locations at which dots will be printed. 
     
     
         28 . The method of  claim 23  further comprising applying a layer of transparent ink or varnish in a manner such that the transparent ink or varnish fills gaps between adjacent dots and substantially equalises height differences arising from dots having different thicknesses. 
     
     
         29 . The method of  claim 23  wherein forming the material layer comprises selecting a composition of the dots and/or a composition variation of the dots within the material layer. 
     
     
         30 . The method of  claim 29  wherein the dots have a transmissivity dependent on the composition of the dots. 
     
     
         31 . The method of  claim 30  wherein the dots are formed using a composition of ink transmissive for visible light and ink not transmissive for visible light. 
     
     
         32 . The method of  claim 31  comprising selecting a ratio of ink or varnish transmissive for visible light and ink not transmissive for visible light. 
     
     
         33 . The method of  claim 29  further comprising applying a layer of transparent ink or varnish in a manner such that the transparent ink or varnish fills gaps between adjacent dots. 
     
     
         34 . The method of  claim 21  wherein the step of forming the material layer comprises forming the visible layer directly or indirectly on a surface of a panel transmissive for light. 
     
     
         35 . The method of  claim 34  comprising forming the material layer directly or indirectly on the visible layer. 
     
     
         36 . The method of  claim 35  further comprising forming a solar cell structure over the formed material layer. 
     
     
         37 . The method of  claim 36  further comprising positioning a glass pane over the formed solar cell structure. 
     
     
         38 . The method of  claim 21  to  29  comprising providing a solar cell structure and forming the material layer directly or indirectly on a surface of the solar cell structure. 
     
     
         39 . The method of  claim 38  comprising forming the visible layer directly or indirectly on the formed material layer. 
     
     
         40 . The method of  claim 39  comprising positioning a glass pane over the formed visible layer.